Thanks for the chapter!
(Is the male teacher being a wingman for Hinohara and middle-schooler Nagai???)
(also would the story make more sense if Nagai were in high school?)
I think this is that weird manga thing where there’s often a notable disjunction between the characters’ stipulated age/grade-level and their appearance/actions. To me, it seems to be the case in any number of series that so-called “middle-schoolers” look and act like late-high-schoolers, and high-school students seem to be 3-5 years older than their grade level.
In the famous manga/anime Akira, we’re told that the MCs, who are out gang-banging and getting wrapped up in apocalyptic political/scientific conspiracies, are all 15 years old. (When I think of me and my friends at 15, we . . .didn’t look or act like that.)